Various types of systems for representing a musical composition are known in the art. One type of such a system is standard staff notation, which is a form of musical notation that specifies the rhythm and duration of notes along with their corresponding pitches on a staff. Another type of system is a tablature for stringed instruments, which is a form of musical notation that specifies where and when to place ones fingers on the stringed instrument, instead of which pitches to play. User interfaces for representing a musical composition, such as tablature editors, the musical instrument digital interface (MIDI) and digital audio workstations (DAWs), allow a user to view a tablature notation representation, a music notation representation (e.g., a music score) or alternatively, a sound signal representation of the sounds (e.g., a waveform).
The user may edit and manipulate the various parameters of the audio information such as the pitch, amplitude and duration of each note in a music notation view of the audio information. The audio information can be manipulated via a user interface to correct playing errors, to compose new music and to modify existing notes. Furthermore, DAWs can also allow the user to apply sound effects to particular segments of the sound or to individual notes. For example, the user may adjust the vibrato of a played note, smooth the transitions between notes, apply flanging effects, shift the formant frequencies of a note or a selection of notes and apply tempo changes.
An example of a DAW known in the art is Melodyne, commercially available by Celemony Software GmbH, which is an audio recording and editing software, having a user interface that allows a user to process and manipulate audio material. Melodyne can be used to analyze audio files in order to identify key aspects of their musical content. Melodyne can recognize individual notes from a recorded musical composition and vary the musical parameters of the notes such as pitch, and time duration.
Reference is now made to FIG. 1, which is a prior art schematic illustration of a graphical user interface (GUI) of an editor display of Melodyne, generally referenced 50. Editor display 50 displays a two-dimensional (2-D) representation of an audio material. Editor display 50 includes an edit pane 52 and a note ruler 54. Note ruler 54 includes a plurality of units, which represent the note symbols of a Western musical system 58. The horizontal axis of edit pane 52 represents time and the vertical axis of edit pane 52 represents pitch.
Edit pane 52 and note ruler 54 are partitioned by a plurality of horizontal lanes 56. Different vertical positions within an area confined by a horizontal lane represent a variation in pitch of at most one tone. A higher vertical position on note ruler 54 indicates a higher pitch and a lower vertical position on note ruler 54 indicates a lower pitch. Melodyne identifies individual notes in the audio material. Each note is represented by a note blob, and is displayed on edit pane 52 at different positions corresponding to the timing and pitch of the respective note.
For example, FIG. 1 depicts nine note blobs 601, 602, 603, 604, 605, 606, 607, 608 and 609 of the audio material. The contour of each of note blobs 601-609 represents a variation of the blob of that particular note amplitude envelope in time (i.e., the manner in which the amplitude of the note changes over time). Each note blob includes a respective pitch curve, labeled 621-629 (i.e., a pitch curve is a curve signifying the variation of the pitch over time). In Melodyne, pitch curves 621-629 are continuous lines that thread through their respective note blobs.
Melodyne also allows a user to manipulate the characteristics of a single note or a phrase (i.e., a musical passage, analogous to a clause in language). For example, the user can transpose notes upward or downward along note ruler 54 and can also vary the pitch of a note at intervals smaller than a tone (i.e., fractional tones). Melodyne can furthermore automatically correct the pitch of a played note (i.e., intonation), for example, if a particular note is played out of tune.
Other features of Melodyne include changing the tempo of the musical piece as well as the timing (i.e., the position and duration) of an individual note by horizontally stretching or squeezing the corresponding note blob. The user can also alter the amplitude of a note by manipulating the shape of the respective note blob amplitude envelope. The user can furthermore cut and paste or drag note blobs at different points in time and at different positions along pitch ruler 54. Melodyne also allows the user to vary the formants (i.e., emphasized resonant frequencies) of musical instruments. For example, by transposing the formants of a voice recording upward, the voice is given a more feminine character. Additionally, Melodyne can display notes on a staff, according to a musical notation representation.